SEXSE-ORGANS IN ANTENNAE AND PALPI OF DIPTERA. 



47 



the pit itself are long and regular, each one I'ising from a thick 

 chitinous ring or collar. Text-fig. 15, from a transverse section 

 through the antenna of Neoitannis cyanurus Loew, shows a pit 

 widely open to the exterior, with short strong processes each 

 again lising from a collar, and having a ridge along its point. 

 Note the bulge in the hypodermal layer formed by the columnar 

 cells, called glandular by Berlese. Text-fig. 16 shows a ti'ansverse 

 section through the palp of Laphria marginata L. ; the w'hole of 

 one surface is broken up into long slender processes, not sunk in 

 pits but arising directly from the surface. Note the thickness of 

 the chitin in these insects. 



Text-figure 16. 



Transverse section thvongh the palp of Laphria marginata. X 980. 



Therevid^ (Text-fig. 17). 



There ai^e, so far as could be ascertained, no pits in the antenna 

 in this family. In the palp of Thereva nobilitaia (text-fig. 17) is 

 a more complicated condition. There is a large sense-pit widely 

 open to the exterior, with long spatulate sensory processes ; also 

 here and there are single trichoid processes. 



EmpiDjE. Species studied determined by C. G. Lamb. 



So far as could be ascertained there are no complicated sense- 

 pits in the forms examined. No special sensory apparatus was 

 visible in the palps of species examined. 



